Symmetrical switch discharge system for inverter branch pair - uses gate controlled semiconductor switches connected to DC voltage source

摘要

Two free wheeling diodes (D1, D2) are respectively in anti-parallel with a semiconductor switch (T1, T2) and a series circuit consisting of a common switch off discharge capacitor (CS), a switch off discharge diode (DS1, DS2) and a storage capacitor (CO1, CO2). A connection of each capacitor makes contact with one of the poles of the DC source (Ud) via an ohmic resistance (RO1, RO2). The choke coils are built as linear choke coils (LK1, LK2), limiting the current rise with the switching on of one of the semiconductor switches. The other connection (not lying at the AC terminal) of the switch off discharge capacitor is connected at the junction of the two storage capacitors, not connected to the ohmic resistance. One of connections of the ohmic resistances is connected directly with one of the poles of the DC voltage source (Ud), and the other connection is applied at the junction of the switch off discharge diode and the storage capacitor within the respective series circuit. USE/ADVANTAGE - Symmetrical switching discharge system for inverter branch pair formed from gate controlled semiconductor switches. Known circuit improved, so that switching discharge is possible at low cost without disadvantages of unsymmetrical commercial system.